The present invention relates to a stackable and nestable container for the transport of material wherein liquid drainage from the container is desired.
Such containers are generally used in the transport and storage of material, which involves vertical stacking of a plurality of containers that are heavily loaded, and therefore require strength in the container. Further strength and rigidity of the container is required in the actual movement of the containers either singly or in stacks from one location to another whether manually, automatically or in stacked condition in the truck or the like transport vehicle. Such movement places considerable stress on the containers. Therefore, the strength and integrity of the containers is a requirement.
Drainage from such containers is provided through an aperture in the bottom of the containers where liquid tends to collect from the material being transported. This is particularly important with respect to such items as fish, wherein ice is many times used to cool the fish, but in doing so the ice melts and produces a liquid that is desirably removed from the container as it is formed. Merely placing one or more holes in the bottom of a container is unsatisfactory, because drainage of one container will be into the next lower container of a stack, so as to provide a cumulative effect of drainage liquid as you proceed vertically down the stack, and more importantly to result in contamination of subsequent lower containers. Contamination would seem to be a considerable problem if there is spoilage of an item towards the top of the stack or if one of the top containers contains a material that does not belong in the container and is detrimental to the material that does belong in the container. Spoilage of material in a container or the presence of material that does not belong in the container can be discovered, and dealt with with respect to that one container, but usually too late to identify lower containers that were stacked with it and thereby contaminated. Even if the other containers that have been contaminated were identified, this would result in considerable wastage.
An important consideration in design of any container is its volume efficiency, which can be expressed as a ratio of its interior useful volume to its exterior required volume when associated with other containers, for example when loading a truck.
While drainage of one container to its outside so as not to contaminate other lower containers in a stack is desired, such is generally detrimental to the container's strength, volume efficiency, economy of manufacture, and other desirable characteristics of the container.